Sodium-free salt substitute

ABSTRACT

A composition that is a substitute for food grade sodium chloride includes crystalline particles containing both potassium chloride and lysine monohydrochloride such that the potassium chloride and lysine monohydrochloride are not susceptible to separation. A process for making the composition includes steps of providing a supersaturated water solution of potassium chloride and lysine monohydrochloride at a temperature of from about 10 to about 70° C., adding ethanol to the solution in an amount sufficient to precipitate crystalline particles containing a combination of potassium chloride and lysine monohydrochloride, separating the crystalline particles from the solution, and drying the crystalline particles.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of PCT Application No.PCT/US2012/052035 filed Aug. 23, 2012 and U.S. Provisional ApplicationNo. 61/575,650 filed Aug. 25, 2011, which are hereby incorporated byreference in their entireties.

FIELD OF THE DISCLOSURE

This disclosure relates to food-grade sodium chloride substitutes.

DESCRIPTION OF PRIOR ART

Health effects such as hypertension have been directly linked to theexcess consumption of dietary salt (sodium chloride) in a number ofstudies. It is widely recognized that an important element of combatinghypertension is the simultaneous reduction of sodium while increasingthe consumption of potassium in the diet. Recently, the U.S. Governmenthas released a new set of standards reducing the recommended dailyallowance of sodium from 2300 mg to 1300 mg. In addition, therequirement for potassium has been set at 4700 mg.

While some products have used the strategy of mixing sodium chloridewith potassium chloride to reduce sodium consumption (see references inU.S. Pat. No. 5,897,908), there are few products on the market that aresodium-free. Potassium chloride by itself has a bitter, metallic tasteand some sort of masking agent must be used to cover this taste.Previously, it was discovered (K. A. Berglund and H. Alizadeh, U.S. Pat.No. 5,897,908 Apr. 27, 1999) that lysine monohydrochloride, an essentialamino acid to human nutrition, was able to effectively mask this taste.The compositions disclosed in U.S. Pat. No. 5,897,908 are a physicalmixture of potassium chloride (KCI) and lysine monohydrochloride (LMC)crystals that provide a salty taste.

SUMMARY OF THE DISCLOSURE

Described herein are improved substitutes for food grade sodium chloridethat provide a salty taste. Such compositions comprise crystallineparticles containing both potassium chloride (KCI) and lysinemonohydrochloride (LMC). Further, the compositions can have a ratio ofKCI to LMC that is between about 90:10 and 60:40 by weight. In certainembodiments, the compositions can have a ratio of KCI to LMC that isbetween about 65:35 and 75:25.

Also disclosed is a process for providing a composition which is asubstitute for food grade sodium chloride. The process includes steps of(a) providing a supersaturated water solution of potassium chloride(KCI) and lysine monohydrochloride (LMC) at a temperature between about10 and 70° C.; (b) adding ethanol to the solution in an amountsufficient to precipitate crystalline particles containing a combinationof LMC and KCI; (c) separating the crystalline particles from thesolution; and (d) drying the crystalline particles to provide thecomposition in a flowable form. In certain embodiments, the watersolution is prepared using water that was ultrafiltered. In certainembodiments, the weight ratio of co-precipitated KCI to LMC is betweenabout 90:10 and 60:40. In certain embodiments, the weight of KCI to LMCratio is between about 65:35 and 75:25. In certain embodiments, ethanolis separated from the water, recycled and reused. The ethanol used inthe process can be an azeotrope with water obtained by a conventionaldistillation, or an anhydrous alcohol obtained by a process such aspressure-swing distillation, azeotrope distillation with a benignentrainer such as pentane, or with molecular sieves.

BRIEF DESCRIPTION OF THE DRAWING

FIG. 1 is a graph of the x-ray diffraction powder patterns of crystalsproduced by anti-solvent crystallization from aqueous mixtures of KCIand LMC.

DETAILED DESCRIPTION

U.S. Pat. No. 5,897,908 disclosed a physical mixture of the two crystaltypes, which presented problems in commercialization that were notanticipated. In particular, the two crystals tended to segregate duringshipping and/or use. In addition, the two crystals are generally notproduced commercially in such a way that they dissolve at the same rate.This difference in dissolution caused difficulties in processing, and,when used in place of table salt, a difference in taste.

The novel process of preparing a KCl/LMC substitute for sodium chlorideinvolves co-precipitation of the two species in a new type ofcrystalline, particulate form. The highly innovative process disclosedherein uses biobased solvents to achieve the desired result. The newproduct generates a single crystalline particulate material in which thechemical species cannot be segregated. Independent taste trialsdemonstrate that the crystalline particulate products disclosed hereinhave a taste that is favored as compared to the physical mixturedescribed in U.S. Pat. No. 5,897,908. The new product was used incracker baking and it was found superior in performance in eliminatingordinary table salt (i.e., sodium chloride) completely.

EXAMPLES

Crystallization conditions were determined for the production of theco-crystallized potassium chloride and monohydrochloride. Previousstudies by Pinho and Macedo (2005) and Zhao et al. (2009) determined thesolubility of KCI and LMC in ethanol/water mixtures, respectively. Ineach case, it was found that the solubilities of each pure compoundreached approximately zero in pure ethanol. Other authors have found asynergistic effect of solubility between KCI and amino acids, but theeffect is relatively small and was not considered important in thecurrent work (Ferreira et al., 2007). Uusi-Penttilä (1997) showed thatLMC could be crystallized from aqueous solution by addition of ethanol.

In order to crystallize a substance, it is required to createsupersaturation. This can be achieved in a number of ways, but in thecurrent work, the use of an anti-solvent crystallization approach wasapplied. The procedure for the crystallization was to prepare a solutionof water with KCI and lysine monohydrochloride (LMC) at a concentrationat or near saturation. All studies were conducted at room temperature,approximately 20° C. The ratio of KCI to lysine monohydrochloride wasvaried from 90:10 to 60:40. Ethanol was slowly added with stirring untila volume ratio of about four times the volume of ethanol was added tothe initial volume of water used in the solution. The products (KCI andLMC) were co-crystallized from solution at high yield and were filteredand dried. Segregation is prevented because the KCI and LMC areintimately combined in a single crystal type. In addition, the startingLMC had a light brown color and the KCI was completely white. Most ofthe color remained in the ethanol solution, but the resulting crystalshad a uniform color indicating a single crystal type. Taste propertieswere assessed. The resulting taste profiles are shown in Table 1.

TABLE 1 Effect of the composition on salty taste of co-crystallizationcrystals. Ratio of KCl:LMC, mass basis Resulting taste 80:20 Salty, butsome bitterness 70:30 Salty 60:40 Less salty

Powder pattern x-ray diffraction is a well established analytical toolto determine the presence of different crystal phases. A series of x-raydiffraction powder patterns were developed for different mass ratios ofKCI to LMC. The results are shown in FIG. 1. The x-ray diffractionpatterns show that the crystalline nature of the LMC is lost as the KCIcontent rises, as evidenced by loss of reflections. While the datasuggests there is some type of amorphous LMC in the presence of the KCI,which could be a coating, it is apparent that the products of the novelprocesses disclosed herein are not the same as physical mixtures of thetwo crystals, since the reflections for individual crystals of the twochemical species have not been retained. Thus, the compositionsdisclosed herein are not necessarily comprised entirely of crystals andmay more appropriately be designated as crystalline particles, whichencompass purely crystalline products, as well as precipitatescomprising a combination of crystalline and amorphous materials in whichthe amorphous materials may be occluded, coated on to, or otherwiseintimately associated with the crystals. Notably, the crystallineparticles that are co-precipitated as disclosed herein produce an x-raydiffraction pattern that does not have peaks at 2 theta values ofapproximately 8, 15 and 53, which are characteristic of crystalscomprised of LMC alone.

A novel crystallization procedure has been developed to produce a newtype of crystalline particulate material that has improved taste andphysical properties for the replacement of dietary sodium chloride. Thestarting solution concentration of potassium chloride (KCI) and lysinemonohydrochloride (LMC) can be approximately 30 weight percent in water.Examples of suitable ratios of KCI:LMC can range from 9:1 to 6:4 byweight, such as from about 65:35 to 75:25 by weight. Crystallization canbe achieved by addition of ethanol to achieve a final range of ratio ofethanol to water from 3:1 to 6:1, such as 4:1 to 5:1. The x-raydiffraction powder pattern of the resulting crystalline particlesindicates the presence of a new lysine phase.

While the present invention is described herein with reference toillustrated embodiments, it should be understood that the invention isnot limited hereto. Those having ordinary skill in the art and access tothe teachings herein will recognize additional modifications andembodiments within the scope thereof. Therefore, the present inventionis limited only by the claims attached herein.

What is claimed is:
 1. A composition which is a substitute for foodgrade sodium chloride providing a salty taste, which comprises:crystalline particles in which the individual particles comprise bothpotassium chloride (KCI) and lysine monohydrochloride (LMC).
 2. Thecomposition of claim 1 wherein the ratio of KCI to LMC is between about90:10 and 60:40 by weight.
 3. The composition of claim 1 wherein theratio of KCI to LMC is between about 65:35 and 75:25 by weight.
 4. Aprocess for providing a composition which is a substitute for food gradesodium chloride, which comprises: (a) providing a supersaturated watersolution of potassium chloride (KCl) and lysine monohydrochloride (LMC)at a temperature between about 10 and 70° C.; (b) adding ethanol to thesolution in an amount sufficient to precipitate crystalline particlesthat contain both LMC and KCI; (c) separating the crystalline particlesfrom the solution; and (d) drying the crystalline particles to providethe composition in a flowable solid particulate form.
 5. The method ofclaim 4 wherein the water is ultrafiltered.
 6. The method of claim 4wherein the weight ratio of KCI to LMC is between about 90:10 and 60:40.7. The method of claim 4 wherein the weight ratio of KCI to LMC isbetween about 65:35 and 75:25.
 8. The method of claim 4 wherein theethanol is separated from the water, recycled and reused.
 9. The methodof claim 4 wherein the ethanol is provided as an azetrope with water.10. A food grade dietary substitute for sodium chloride comprisingcrystalline particles containing potassium chloride and lysinemonohydrochloride, wherein an x-ray diffraction pattern for the productdoes not have peaks at 2 theta values of approximately 8, 18 and 53,which are characteristic of lysine monohydrochloride crystals alone.